Investigations of formation process of a complex hydride with high hydrogen densities and exploration of new hydrides

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K06766
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: Tohoku University
• Principal Investigator: Sato Toyoto 東北大学, 金属材料研究所, 助教 (20455851)
• Research Collaborator: Takagi Shigeyuki ; Ikeda Kazutaka
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: エネルギー材料 / 結晶構造 / 振動ダイナミクス / 錯体水素化物

Outline of Final Research Achievements

Complex hydrides with covalently bonded hydrogen have potential for hydrogen storage materials because of the high hydrogen densities. Although the formation (hydrogenation) and decomposition (dehydrogenation) processes of the complex metal hydrides is of fundamental and technological interest, they have not been understood properly. In this study, we elucidated hydrogenation and dehydrogenation processes of a complex hydride LaMg2NiH7. In the hydrogenation process, intermediate phases existed before the formation. In the dehydrogenation process, chemical bonds around hydrogen atoms weakened before the decomposition. In particular, the metal atomic arrangements are maintained during the hydrogenation process, which proceeded at room temperature. This was much lower temperature than typical complex hydrides. Therefore, the maintaining metal atomic arrangement during the hydrogenation process is one important for guideline of designing hydrogen storage materials at moderate conditions.

Free Research Field

材料工学

Academic Significance and Societal Importance of the Research Achievements

本研究から、これまで未解明であった高密度に水素を含有する錯体水素化物の形成・分解反応機構が明らかになるとともに、室温で錯体水素化物の形成反応が進行するための知見が得られた。これらの結果により、将来の水素社会で不可欠な室温付近で水素を高密度に貯蔵できる材料を実現することが期待される。
また、本研究では、原子・分子の観点で得られた知見を材料特性にフィードバックし、錯体水素化物の形成・分解機構を解明した。このような研究遂行方法と得られた知見は、無機物質の新規物質探索研究の全般において不可欠な情報であり、化学、物理学、材料科学、結晶学など学術的な分野の発展にもつながる。